大倾角煤层回采巷道断面适应性

Adaptability of Roadway Section Shape in Deep Inclined Seam

基于大倾角煤层回采巷道围岩应力显现规律,采用数值分析方法对不同类型断面巷道的围岩塑性区及应力非对称分布特征进行研究,并建立异形断面巷道围岩破坏力学模型,确定其合理的支护方式.结果表明,大倾角煤层回采巷道围岩塑性区沿煤层倾斜方向演化,顶底板破坏深度大于两帮,且两帮破坏程度差异大;巷道断面形状不同,导致巷道围岩应力集中程度、塑性区及变形量等有很大差异;拱形巷道围岩变形适应性好,异形巷道两侧的顶角煤易发生剪切破坏,但考虑回采巷道掘进、设备运行及服务年限等需求,常用异形巷道;采用"锚网+钢带+锚索"的支护形式,加强异形巷道顶板帮及坡顶煤的支护,满足支护阻力大于F1和F2,可明显减少巷道围岩变形,保持巷道的稳定性.

Based on distribution of surrounding rock stress in deep inclined seam roadway,the asymmetric distribution lawof the plastic zone and stress of different cross-section roadway were studied by using numerical method,and a mechanical model of special-section roadway was established to determine the reasonable support mode. The results showthat deep inclined seam roadway plastic zones extend along the dip direction of coal seam,failure of roof and floor is greater than that of ribs,and what is more,different damage and failure occur in ribs; the roadway shape affects the stress concentration,plastic zone and deformation; arched roadway adapts well,and special-shaped tunnel is likely to lead to shear failure-prone in the roof side corner,but taking roadway service life and mining issues into account,special-shaped tunnel can meet the requirements under the existing support conditions. The combination supports of ＂anchor net ＋ steel band ＋ anchor rope＂are adopted to strengthen the rib beside roof and the roof coal for special-shaped tunnel,and the support stress should be above F1 and F2. By this way,surrounding rock deformation is obviously reduced and the roadway can stay stable.